In adults over age 50 living independently, having a chronic illness greatly increases risk of depressive episodes, according to a Statistics Canada survey – and the highest rates of depression among the 36 illnesses tracked are chronic fatigue syndrome (30% of patients); fibromyalgia (14%); and migraine (9%).

By comparison, although fully 82.4% of the overall survey population reported having one or more chronic conditions, only 3.7% of them reported depression. And only 1.0% of the survey population reporting no chronic conditions were depressed.

The data, collected in 2002 and reported by University of Calgary researchers in the June issue of the Journal of Affective Disorders*, is based on analysis of nearly 16,000 survey responses.

This new awareness of depression risks should focus attention on prevention and treatment efforts for the chronically ill, says Kirsten Fiest, a lead author of the report.

And to make matters worse for the chronically ill, “Depression can affect cognitive function, creating difficulty in adhering to treatments,” says U of Calgary professor Dr. Scott Patten. “It also zaps people of the energy and optimism that are so badly needed in coping with chronic illnesses. In some instances, it makes symptoms worse. For example, depression tends to magnify the experience of pain.”